INTERNATIONAL: Portugal built Europe's largest floating solar park: 12,000 solar panels of the size of four soccer pitches floating on Alqueva reservoir.

Built by the country's main utility EDP, the project is part of Portugal's plan to cut reliance on imported fossil fuels.

The panels on the Alqueva reservoir will produce 7.5 gigawatt/hours of electricity a year, with lithium batteries to store 2 gigawatt/hours.

They will supply 1,500 families - about a third of the power needs of the nearby towns of Moura and Portel.

Miguel Patena, EDP group director in charge of the project, said that the cost of electricity of these types of projects is less than one-third, or 25%, of the cost of the fuel fired in power plants nowadays.

Solar panels mounted on lakes or at sea have been installed in a range of places from California to China.

Floating panels do not require valuable real estate and those on reservoirs used for hydropower are particularly cost effective as they can hook up to existing links to the power grid.

Excess power generated on sunny days can also pump water up into the lake to be stored for use on cloudy days or at night.

In 2017, EDP installed a pilot floating solar project on the Alto Rabagao hydro dam.

It was the first in Europe to test how hydro and solar power could complement each other. This will reduce the dependency of carbon fuels and reduce the prices of the pool markets.